Screen potential prostaglandin antagonist activity in the cardiovascular and renal systems. Define the antagonist activity as to whether prostaglandins, prostaglandin receptors, or prostaglandin producing enzymes are being blocked. Determine whether the antagonist is competetive or noncompetitive. Determine the degree of speciicity of the effective antagonists. Determine the degree of toxicity of the effective antagonists. Determine the degree of chemical stability of the effective antagonists.